import React, { Component } from 'react'
import './index.css'

export default class Footer extends Component {

  // 全选
  handleCheckAll = (event)=> {
    this.props.checkAllTodo(event.target.checked)
  }

  handleClearAllDone = ()=>{
    this.props.handleClearAllDone()
  }

  render() {
    const {todos} = this.props

    const doneCount = todos.reduce((pre, todo)=>{
      return pre + (todo.done ? 1 : 0) 
    }, 0)

    const total = todos.length

    return (
      <div className="todo-footer">
        <label>
          <input 
          type="checkbox" 
          onChange={this.handleCheckAll}
          // defaultChecked={doneCount == total}
          checked={doneCount === total && total!== 0 ? true : false}
          />
        </label>
        <span>
          <span>已完成{doneCount}</span> / 全部{total}
        </span>
        <button className="btn btn-danger" onClick={this.handleClearAllDone}>清除已完成任务</button>
      </div>
    )
  }
}
